The present invention relates to a compressor for compressing a gaseous fluid and, more particularly, to a compressor having a valve mechanism in a gas passage for preventing a back flow of the gaseous fluid.
A conventional compressor is disclosed in Japanese Unexamined Patent Publication (JP-A) No. 5-231351. The conventional compressor is generally called a scroll type compressor and is used for circulating a gaseous fluid in an endless circuit. The conventional compressor includes a compressing chamber for compressing the gaseous fluid, a discharge chamber for receiving the gaseous fluid discharged from the compressing chamber, and a gas passage connected between the compressing chamber and the discharge chamber. For preventing a back flow of the gaseous fluid, the compressor is provided in the gas passage with a valve mechanism or a check valve which will later be described in detail in conjunction with the drawing.
The valve mechanism comprises a valve seat and a valve body opposite to the valve seat. When seated on the valve seat, the valve body closes the gas passage. When removed or apart from the valve seat, the valve body opens the gas passage. In the valve mechanism used in the conventional compressor, the valve seat is formed integral with the gas passage. In other words, the gas passage is made or worked to have the valve seat as a part thereof.
In order to prevent the back flow of the gaseous liquid by the valve mechanism, it is necessary to make the valve seat have high accuracy. However, it is difficult or hard to make the valve seat in high accuracy because the valve seat is formed integral with the gas passage.